Showing papers on "Feed horn published in 2014"
Patent•
12 Sep 2014
TL;DR: In this article, a microwave feed horn including a central resonant elongated cavity open at a distal end and including a series of electromagnetic emission or reception sources at a proximal end and having series of ridges along a wall thereof is described.
Abstract: A microwave feed horn including: a central resonant elongated cavity open at a distal end and including a series of electromagnetic emission or reception sources at a proximal end and having a series of ridges along a wall thereof; and an axial elongated dielectric spear element extending from the distal to proximal end, the spear element acting to increase the beam width of any transmitted or received electromagnetic energy at high frequencies.
149 citations
Patent•
[...]
TL;DR: An antenna includes a receiver, a horn, a lens, and an anti-reflection layer as mentioned in this paper, and the anti-reflective layer includes a dielectric material and is disposed on the first surface of the lens.
Abstract: An antenna includes a receiver, a horn, a lens, and an anti-reflection layer The horn has a first end disposed on the receiver and a second end defining an aperture positioned opposite the receiver The lens is disposed within the aperture of the horn and has a first surface facing inward toward the receiver and a second surface opposite the first surface and facing outward away from the horn The anti-reflection layer includes a dielectric material and is disposed on the first surface of the lens Moreover, the anti-reflection layer defines holes arranged in a 50/50 material to void ratio and that have a thickness of a quarter wavelength of a signal received by the antenna
147 citations
TL;DR: In this paper, a corrugated conical horn antenna using 3-D print technology or stereolithography is presented, which achieves a measured peak gain of 19.6 dBi at 16 GHz with a 1.92:1 VSWR from 11 to 18 GHz.
Abstract: We present the development of a Ku-band (10-16 GHz) corrugated conical horn antenna using 3-D print technology or stereolithography. The antenna is printed using acrylonitrile butadiene styrene (ABS), a thermoplastic, and then coated with conductive aerosol paint. The designed antenna achieves a measured peak gain of 19.6 dBi at 16 GHz with a 1.92:1 VSWR from 11 to 18 GHz. It is shown that 3-D printing is capable of producing sufficient feature sizes that make operation in the microwave/millimeter-wave (MMW) bands possible.
128 citations
TL;DR: In this article, a phase corrected substrate integrated waveguide (SIW) H-plane horn antenna with embedded metal-via arrays is presented, where the SIW horn is divided into four subhorns by three metalvia arrays inside the horn.
Abstract: A novel phase corrected substrate integrated waveguide (SIW) H-plane horn antenna with embedded metal-via arrays is presented. The SIW horn is divided into four subhorns by three metal-via arrays inside the horn. A uniform phase distribution of EM field across the horn aperture is achieved by adjusting the lengths and positions of the metal-via arrays. The proposed horn antenna has a compact profile, and its simulated gain is 7.50 dBi at 35.5 GHz, whereas the simulated gain of a traditional horn antenna without the metal-via arrays is 6.38 dBi. When measured, the gain of the proposed horn antenna is 7.87 dBi at 35.5 GHz, whereas the gain of the traditional horn antenna is 5.58 dBi. Good agreement between the simulated and the measured results is obtained.
124 citations
27 May 2014
TL;DR: The first channel sounder based on automatically rotating horn antennas with time synchronization ability with synthesized omni-directional propagation measurement results in millimeter wave 28 GHz band is introduced.
Abstract: The millimeter wave band will be a key component in the next generation wireless communication system (5G), and a proper channel model is needed for developing the future 5G cellular technologies. This paper introduces a 28 GHz channel sounder based on automatically rotating horn antennas with time synchronization ability between the transmitter (TX) and the receiver (RX). We have developed a sounding method for synchronized measurement using the proposed channel sounder system which records time-stamping to measure the relative propagation time from the transmitter to receiver. The proposed approach allows us to generate an omni-like channel measurements by synthesizing all directional measurements, which have been verified by comparison with the measurements of omni-directional antennas. Subsequently, the omni-directional propagation measurement results are provided in an in-building environment similar to a small shopping mall. From the measurements, the clustering analysis has been done including its power distribution. This paper provides the first channel sounder and initial results to obtain the synthesized omni-directional results in millimeter wave 28 GHz band.
120 citations
TL;DR: In this article, a substrate integrated waveguide (SIW) horn antenna loaded with air-via perforated dielectric slab for bandwidth enhancement is proposed, which can enhance the impedance bandwidth of the antenna in much degree.
Abstract: A substrate integrated waveguide (SIW) horn antenna loaded with air-via perforated dielectric slab for bandwidth enhancement is proposed in this letter. The narrow impedance bandwidth of the planar horn antenna is mainly resulting from the discontinuity between the substrate and air. By simply drilling air-vias with different diameters in the substrate extended from the horn aperture, a smooth transition from substrate to air can be achieved, which can enhance the impedance bandwidth of the antenna in much degree. Measured results show that the enhanced impedance bandwidth of 40% from 16 to 24 GHz is obtained with the return loss |S11| below -10 dB. In addition, stable radiation patterns are observed over the entire operating band.
113 citations
TL;DR: In this article, a conical moderate-gain horn antenna is integrated with a planar inhomogeneous dielectric flat transmit-array lens having diameter of 35 mm and thickness of 6.35 mm by covering its aperture.
Abstract: The design of lightweight, compact-size, and high-directivity conical horn lens antenna that covers both 71-76 and 81-86 GHz bands is presented in this letter. The conventional conical moderate-gain horn antenna is integrated with a planar inhomogeneous dielectric flat transmit-array lens having diameter of 35 mm and thickness of 6.35 mm by covering its aperture. The transmit-array lens is designed based on the perforating dielectric technique that is based on the drilling of numerous holes of variable diameters through a dielectric host material. The unit cell size is about λ0/2, which allows for easier fabrication. The proposed lens consists of eight concentric zones of same width of 2.32 mm and sharing the same host dielectric material. A directivity of 26.4 dBi, 9 dBi improvement, sidelobe level (SLL) of -15.7 dB at 74 GHz and directivity of 27 dBi, 9.9 dBi improvement, and SLL of -18.4 dB at 86 GHz were achieved. The proposed horn antenna is 44.46% shorter than the conventional horn antenna producing the same directivity, where the horn antenna length reduction is a result of using the proposed transmit-array lens.
85 citations
TL;DR: SuperSpec as mentioned in this paper is an ultra-compact spectrometer-on-a-chip for mm and submm wavelength astronomy with planar, lithographed, superconducting transmission line resonator filters.
Abstract: SuperSpec is an ultra-compact spectrometer-on-a-chip for mm and submm wavelength astronomy. Its very small size, wide spectral bandwidth, and highly multiplexed detector readout will enable construction of powerful multi-object spectrometers for observations of galaxies at high redshift. SuperSpec is a filter bank with planar, lithographed, superconducting transmission line resonator filters and lumped-element kinetic inductance detectors made from Titanium Nitride. We have built an 81 detector prototype that operates in the 195–310 GHz band. The prototype has a wide-band metal feed horn with a transition to microstrip that feeds the filter bank. The prototype has demonstrated optical filter bank channels with a range of resolving powers from 300 to 700, measured fractional frequency noise of 10^(−17)Hz^(−1) at 1 Hz.
46 citations
TL;DR: In this article, a broadband reflector feed is presented, which consists of a dielectric extended hemispherical lens fed by a connected array of leaky-wave slots.
Abstract: A broadband reflector feed is presented, which consists of a dielectric extended hemispherical lens fed by a connected array of leaky-wave slots. The slot elements are coherently combined to generate directive radiation patterns that mostly illuminate the central part of the lens, the most efficient one. The array is capable of producing secondary patterns with almost constant -10 dB beamwitdh over a 3:1 bandwidth. This allows efficient illumination of the reflector over a wide frequency range. Performance is estimated in terms of amplitude taper and phase error losses at the reflector, yielding efficiency of about 80% over the entire 3:1 bandwidth. Although the envisaged applications are in the terahertz (THz) and mm-wave frequency bands, a low-frequency prototype demonstrator has been tested in the 4 to 12 GHz band, for experimental validation of the concept.
29 citations
TL;DR: In this paper, a dual-band dual-polarized planar passive phased array feed was designed and simulated, with four highly isolated ports and polarizations, for the deployment of a satellite transponder that transmits a downlink signal at 17.3-17.8 GHz.
Abstract: A dual-band dual-polarized planar passive phased array feed was designed and simulated, with four highly isolated ports and polarizations. The feed design provides an important feasibility demonstration for the deployment of a satellite transponder that transmits a downlink signal at 17.3-17.8 GHz, referred to as reverse band (RB), in the same orbital slot as an existing Ku-band satellite. The design utilizes a multilayer printed circuit board (PCB) to separate the complex feed distribution networks required for the four-port antenna. Simulation results indicate that the feed receives signals in dual linear polarization at Ku-band and dual circular polarization at RB with isolation between all ports better than 20 dB. With the feed illuminating a reflector antenna, the aperture illumination and radiation efficiencies are approximately 70% and 80%, respectively, for all ports, representing one of the most complex yet efficient reported planar array feed designs in the literature.
24 citations
06 Apr 2014
TL;DR: In this article, a quadraxial feed, excited by two orthogonal differential modes, is proposed for ultra wideband quadruple-ridged flared horn (QRFH) antennas that obviates the need for a balun.
Abstract: A quadraxial feed, excited by two orthogonal differential modes, is proposed for ultra wideband quadruple-ridged flared horn (QRFH) antennas that obviates the need for a balun. It is shown that in this configuration the fundamental TE11 mode is most strongly excited over the entire frequency band, while the higher-order modes are significantly suppressed, as compared to the conventional excitation using the ridge-to-coax balun transition. These properties lead to several advantages for QRFH antenna applications which require frequency-invariant beam characteristics, high port isolation and low cross-polarisation level, such as e.g. reflector antenna feeds for future radio telescopes.
TL;DR: In this article, a hybrid numerical technique is applied for the analysis of circularly symmetric dual reflector antenna fed by TEM coaxial horn to generate an omnidirectional radiation pattern.
Abstract: A hybrid numerical technique is applied for the analysis of circularly symmetric dual reflector antenna fed by TEM coaxial horn to generate an omnidirectional radiation pattern. By following the steps of a technique developed for the analysis of horn antennas, it employs a stepped-waveguide method to analyze the interior surfaces of the TEM coaxial horn transition and the electric field integral equation (EFIE) is applied on the outer surfaces of the TEM coaxial horn including the radiating aperture and the reflectors. Simultaneously, the magnetic field integral equation (MFIE) is employed on the aperture to relate the aperture fields and those in the horn transition. Method of moments (MoM) is employed to numerically solve the resultant hybrid field integral equation. The technique is applied for electromagnetic analysis of a coaxial TEM horn antenna and an omnidirectional dual reflector antenna. Results for the antenna return loss at the input port and for the vertical radiation pattern are given and compared with measurements and with commercial software results.
TL;DR: In this paper, a modified primary reflector was proposed to increase the maximum frequency for primary-focus operation and also improve low-frequency multifeed capabilities of the 64m Sardinia Radio Telescope (SRT).
Abstract: The 64-m Sardinia Radio Telescope (SRT) is a shaped dual-reflector antenna designed to optimize secondary-focus operations. A novel application of the SRT active primary reflector aimed at achieving efficient operations also at the primary focus is presented. To this purpose, we show how the panels of the shaped primary mirror can be moved to best fit a parabolic surface. The modified primary reflector permits increasing the maximum frequency for primary-focus operation and also improves low-frequency multifeed capabilities. In fact, our numerical simulations show that at 80 GHz, the aperture efficiency from the primary focus drops only 10% with respect to 300 MHz.
TL;DR: In this paper, a flat ultra-wideband 2D reflector designed using transformation optics (TO) is presented, which mimics the electromagnetic characteristics of a curved parabolic reflector that is rotated about its apex to reflect the incident wave to a prescribed direction.
Abstract: This paper presents the design and experimental validation of a flat ultra-wideband 2-D reflector designed using transformation optics (TO). The flat TO reflector mimics the electromagnetic characteristics of a curved parabolic reflector that is rotated about its apex to reflect the incident wave to a prescribed direction. The TO reflector is true-time-delay (TTD) in nature and it offers a very large bandwidth which is theoretically unconstrained. The proof-of-concept TO reflector design is explored by employing an effective material with an inhomogeneous electric response which is realized by an array of dipoles. We experimentally verify the principle of operation of the reflector over a 67% bandwidth and show that it maintains good radiation characteristics and low beam squint. The design considerations, benefits and drawbacks of the proposed TO reflector are discussed.
TL;DR: In this article, a direct and unambiguous approach to determine the focal point of a single offset reflector is presented based on iteratively defocusing the primary feed laterally and axially.
Abstract: A direct and unambiguous approach to determine the focal point of a single offset reflector is presented. The proposed approach makes use of the vectorial form of far-field radiation patterns, both amplitude and phase. The method is based on iteratively defocusing the primary feed laterally and axially. First, mathematical expressions of the offset reflector with a small lateral and axial defocused feed are reviewed. Then, the numerical results are presented. It is shown how the corresponding far-field phase pattern information can be utilized to optimally locate the focal point of an offset parabolic reflector. The method can also be used to place the phase center of an unknown feed on the reflector focal point, and align the reflector on a test tower.
06 Jul 2014
TL;DR: In this paper, a high gain hybrid DRA/horn antenna for millimeter-wave (MMW) application is proposed, which employs a slot coupled cylindrical DRA to excite a thin-wall surface mounted circular horn.
Abstract: A high gain hybrid DRA / horn antenna for millimeter-wave (MMW) application is proposed. The antenna employs a slot coupled cylindrical DRA to excite a thin-wall surface mounted circular horn. The optimized design exhibits an operating frequency range from 29.6 GHz to 30.75 GHz with a bandwidth of 3.8%. The surface mounted horn enhances the total realized gain to 11.2 dB. A very good agreement has been achieved between both the numerical simulations (CST MWS and HFSS) and measurements.
Patent•
11 Jul 2014TL;DR: In this paper, a dual-mode radio system with a first radio unit including a transmitter, a receiver, an antenna, and switching circuitry adapted to couple either an output of the transmitter to the receiver or an input of the receiver to the antenna of the first unit is described.
Abstract: Embodiments of a dual-mode radio system are disclosed. In one embodiment, the radio system includes a first radio unit including a transmitter, a receiver, an antenna, and switching circuitry adapted to couple either an output of the transmitter of the first radio unit or an input of the receiver of the first radio unit to the antenna of the first radio unit. In addition, the radio system includes a second radio unit including an antenna and either a transmitter having an output coupled to the antenna of the second radio unit, a receiver having an input coupled to the antenna of the second radio unit, or both a transmitter having an output selectively coupled to the antenna of the second radio unit and a receiver having an input selectively coupled to the antenna of the second radio unit. The radio system has both a full-duplex mode and a half-duplex mode.
TL;DR: In this paper, a frequency-scanning grating-reflector antenna operating in the 0.2 THz band is proposed, which consists of a planar grating reflector, a thin lens and a feed horn placed at the focal point of the lens.
Abstract: A frequency-scanning grating-reflector antenna operating in the 0.2 THz band is proposed. The antenna system consists of a planar grating reflector, a thin lens and a feed horn placed at the focal point of the lens. The beam-scanning property based on the frequency sweeping was analysed and optimised based on Floquet's theorem. A bilayer structure is introduced to improve the diffraction efficiency and to suppress the specular beam. The frequency-controlled beam steering concept was verified by the quasi-optical measurements in the 0.2 THz band. The measured scanning range is 13.55° over the frequency band 180–220 GHz. The specular beams are remarkably inhibited with the diffractive efficiency as high as over 89%. The presented antenna has the advantage of the convenience to be extended to a higher frequency with a high directivity.
TL;DR: In this paper, a planar binary structure was proposed to improve the diffraction efficiency and suppress the specular beam in the 0.2-Terahertz (THz) band.
Abstract: A novel frequency-scanning grating-reflector antenna operating in 0.2-Terahertz (THz) band is studied in this letter. The diffraction enhancement mechanism based on the planar binary structure was first proposed to improve the diffraction efficiency and to suppress the specular beam. Compared to the grating-reflectors with multilayered structures that have been implemented in microwave band, the proposed planar binary structure employs a periodic binary grating array and a single-layer substrate, which brings much convenience of fabrication and being extended to the THz band. The antenna system consists of a planar grating-reflector, a thin lens, and a feed horn placed at the focal point of the lens. The frequency-controlled beam-steering concept and the diffraction enhancement mechanism were verified by the quasi-optical measurements in 0.2-THz band. The measured scanning range is 15.45 $^{\circ}$ over the frequency band 180–220 GHz. The specular beams are remarkably inhibited with the diffraction efficiency as high as over 96%. The proposed beam-steering antenna has potential applications for THz imaging with high frame rate.
19 May 2014
TL;DR: In this paper, a compact quad-ridged horn antenna (QRH) for the deep ground penetrating radar water detection applications is designed operate in frequency range of 50MHz to 500MHz.
Abstract: A compact quad-ridged horn antenna (QRH) for the deep ground penetrating radar water detection applications is designed operate in frequency range of 50MHz to 500MHz. Within this contribution the design and simulation of such an antenna is considered for water level detection in Egyptian dessert aquifers. Among the varying horn design parameters, the linear and exponentially tapered walls are studied as well as variations of the curvature of the dielectric waveguide between the two ridges enhancing the matching conditions hence, reducing size and increasing the antenna operational bandwidth. The design goal is to achieve broad bandwidth antenna with maintaining compact dimensions. Two modifications have been introduced on the conventional triangular TEM horn antenna. First multifunction tapering of the horn plates with curvature ending, second inserting perturbing two different ridges between the aperture planes and filling the space between the ridges with high dielectric constant material, in order to lower the operating frequency without increasing the size of the original setup. Replacing the two ridges with four ones, each pair is perpendicular to the other, reduces more the antenna size and improves more its matching. The antenna dimensions are 145 × 102 × 124 cm
3
that resembles improvement in size as compared with similar commercial GPR horn antennas as Satimo Horn model SH 68 with dimensions 2983×1615×2505 cm
3
.
01 Sep 2014
TL;DR: In this article, a double-ridged guide horn (DRGH) antenna with coaxial input feed section is presented, which is suitable to be used in electromagnetic compatibility testing and antenna measurement as a transmitter.
Abstract: In this paper, simulation and measurement results of 0.7-7 GHz double-ridged guide horn (DRGH) antenna with coaxial input feed section is presented. This antenna, due to the large frequency band required by standards, is appropriate to be used in electromagnetic compatibility (EMC) testing and antenna measurement as a transmitter. A step by step method for designing DRGH antenna is given. A suitable taper for the ridges in the horn is designed and its impedance variations along the horn are shown. In addition, a new structure for the electrical field probe in the feed section is introduced by which a shift-down of lower frequency to 0.7 GHz is achieved. A sensitivity analysis is done on the parameters of the proposed structure. Other parameters of the feed section are also investigated and optimized values are obtained. Finally, the proposed antenna has been fabricated and measurement results show good agreement with the simulation.
06 Jul 2014
TL;DR: In this paper, a smooth walled spline feed horn antenna for the satellite borne climate research instrument STEAMR operating at 340 GHz was designed, fabrication and measurements of the horn antenna were performed.
Abstract: We present the design, fabrication and measure-ments of a smooth walled spline feed horn antenna for the satellite borne climate research instrument STEAMR operating at 340GHz. A method has been developed which, for a certain desired beam waist, can be used to optimize the horn profile for high Gaussicity and ultra-low sidelobes. The simulated performance of the horn achieves a beam waist of 1.9 mm over the band 323-357 GHz with Gaussian coupling efficiency exceeding 98%. The peak cross-polar sidelobes are below -28 dB over the required frequency band. For cost effective manufacturing with high repeatability, the smooth wall spline profile is drilled in out from a metal block using a custom made broach. To validate the design and fabrication, planar measurements of the phase and amplitude have been performed and from measured E-field vital horn parameters have been extracted.
14 Apr 2014
TL;DR: The obtained results from HFSS simulation concerning the constitutive parameters of the Split Ring Resonator (SRR), show that there is a DNG (Double Negative) permeability and permittivity in the frequency of interest.
Abstract: A Split Ring Resonator (SRR) as Metamaterial has been loaded on pyramidal horn antennas for Ku band or satellite application. The aim of this work is to exhibit the advantage of metamaterial (SRR) use inside horn antenna; this is mainly enhancement of the bandwidth towards lower frequency and improvement of the radiation pattern gain. The horn antenna is feed by a monopole antenna of optimized length. The obtained results from HFSS simulation concerning the constitutive parameters of the (SRR), show that there is a DNG (Double Negative) permeability and permittivity in the frequency of interest. In this work the operating bandwidth of the proposed antenna (notched band) is in the range of 9.80 GHz to 10.30 GHz, and 10.80 GHz to 11.20 GHz as Ku or satellite application.
Patent•
26 Mar 2014
TL;DR: An antenna system for triple-band satellite communication according to one exemplary embodiment of the present disclosure includes a feed horn device that is configured to simultaneously radiate or absorb wireless signals of triple bands including X, Ku and Ka bands, and a waveguide section that is coupled to the feed horn devices and configured to transmit input and output of the wireless signals as mentioned in this paper.
Abstract: An antenna system for triple-band satellite communication according to one exemplary embodiment of the present disclosure includes a feed horn device that is configured to simultaneously radiate or absorb wireless signals of triple bands including X, Ku and Ka bands, and a waveguide section that is coupled to the feed horn device and configured to transmit input and output of the wireless signals, wherein the feed horn device includes a corrugation horn that is configured to radiate or absorb the wireless signals of the X and Ku bands, the corrugation horn having a bell-like shape with a plurality of corrugations formed on an inner circumferential surface thereof in a stepped manner, and a dielectric feed horn that is configured to radiate or absorb the wireless signal corresponding to the Ku band and disposed in a central region of the corrugation horn.
TL;DR: In this paper, a Potter horn and a compact orthomode transducer operating at 150 GHz were designed using full wave analysis, and the transmission test results showed that the transmission bandwidth (S-11 < -20 dB) is 16 GHz.
Abstract: A Potter horn and a compact orthomode transducer operating at 150 GHz are designed using full wave analysis. The Potter horn patterns have good symmetry within the main beam, the sidelobe level is less than -35 dB, and the cross-polarization level reaches 21 dB. The transmission test results of the orthomode transducer and feed horn show that the bandwidth (S-11 < -20 dB) is 16 GHz. The whole dimension is only (25 mm x 20 mm x 70 mm), whereas the orthomode transducer dimension is (25 mm x 20 mm x 30 mm).
TL;DR: In this article, the Kirsch's image reconstruction method is validated using an experimental setup for scattered field measurement, where two standard double-ridged horn antennas working in frequency range of 1-18 GHz are used inside an anechoic chamber to collect multistatic scattered fields of a hard target.
Abstract: In this letter, the Kirsch's factorization image reconstruction method is validated using an experimental setup for scattered field measurement. In this setup, two standard double-ridged horn antennas working in frequency range of 1-18 GHz, one as a transmitter and the other as a receiver, are used inside an anechoic chamber to collect multistatic scattered fields of a hard target. The transmitter is farther from the target than the receiver. While the transmitter is fixed, the target and receiver are rotated on a turntable. Equivalently, the transmitter and the receiver are evenly rotated on the circular arcs with different radii about a fixed target. The antennas are facing each other so that the receiver does not shadow the target. The hard target is an elongated cylinder with a plus-shape cross section of side 12 cm. Successful imaging shows the validity of the measured multistatic data and the inversion method.
06 Apr 2014
TL;DR: In this paper, an EBG antenna is built with a semi-reflective screen over a set of horns feeding a reflector, where the partial spreading of the electro-magnetic field in such a structure is used to provide ''overlapped radiating apertures'' which generate "overlapping beams" when feeding the reflector.
Abstract: An `EBG antenna (Electro-Magnetic Band Gap)' is built with a semi-reflective screen over a set of horns feeding a reflector. A clever application of the partial spreading of the electro-magnetic field in such a structure is to provide `overlapped radiating apertures', which generate `overlapped beams' when feeding a reflector. This is a unique single-antenna solution, fitting with multi-beams missions from satellite which require low gain ripple over a regional coverage, e.g. for high data-rate communication in Ka-band. A prototype has been optimised and built, as a co-operation between Thales Alenia Space France & XLIM/Antenna Lab, supported by space agencies ESA & CNES. Adding a very light meanderline polariser (honeycomb based) transforms the alternated orthogonal linear polarisations into orthogonal circular ones, coping with most recent missions.
TL;DR: In this article, the cross-polarization properties of multi-phase-center parabolic reflector antennas, illuminated by over-moded primary feeds, have been investigated and a simple array technique with a simple signal processing is used for the symmetric case, whereas a trimode primary feed is employed for the offset case.
Abstract: This letter addresses the cross-polarization properties of electronically controlled multi-phase-center parabolic reflector antennas, illuminated by over-moded primary feeds. Due to the presence of the higher-order modes in the primary feed, the secondary cross-polarization levels deteriorate in the case of symmetric reflector antennas. As for the offset reflectors, the primary multimode feed required to displace the phase-center location may produce a significant crosstalk in the orthogonal polarization. It is shown how one can improve the cross-polarization performances of aforementioned adaptive antennas, which are capable of providing axial beams while their phase-center locations are displaced. The conventional array technique with a simple signal processing is used for the symmetric case, whereas a trimode primary feed is employed for the offset case.
Patent•
19 Nov 2014
TL;DR: In this paper, a high frequency corrugation feed horn with low surface roughness and without a chamber in the annual teeth can be obtained using a precise electroforming method, which greatly enhances the structure strength of a feed horn manufactured with the electroforming technology.
Abstract: The invention provides a precise electroforming method for making the subtle structure of a high frequency corrugation feed horn. The feed horn is obtained in the following way: an electroforming mandrel of the feed horn is made according to the structure form of the inner chamber of the corrugation feed horn; after the treatment that the surface of the mandrel is additionally coated with an anti-corrosion layer, with the combined action of ways of pictographic anode, cathode rotation, plating solution jet flow, bidirectional pulse, physical polishing and grinding, and so on, the mandrel is precisely electroformed with copper so that a feed horn electroformed piece is obtained; the demoulding operation of the electroformed piece and the mandrel is performed so that a feed horn is obtained. With the precise electroforming method of the invention, the problem that the inner corrugations, with a high depth-to-width ratio, of a high frequency corrugation feed horn are difficult to process is solved. With the precise electroforming technology, a high frequency corrugation feed horn with low surface roughness and without a chamber in the annual teeth can be obtained. The precise electroforming method greatly enhances the structure strength of a feed horn manufactured with the electroforming technology. At the same time, the low surface roughness of the horn surface effectively enhances the transmission reliability of microwave signals.
Patent•
30 Jul 2014
TL;DR: In this article, the authors proposed a box-shaped fan-beam antenna, which consists of a feed horn, a main cylindrical reflector, an auxiliary cylindric reflector and an upper cover plate.
Abstract: The invention provides a box-shaped fan-beam antenna. The box-shaped fan-bean antenna comprises a feed horn, a main cylindrical reflector, an auxiliary cylindrical reflector, an upper cover plate, a lower cover plate, a left baffle and a right baffle. The Cassegrain antenna geometric form is adopted in a bus of the main cylindrical reflector and a bus of the auxiliary cylindrical reflector, the upper side of the main cylindrical reflector, the lower side of the main cylindrical reflector, the left side of the main cylindrical reflector, the right side of the main cylindrical reflector, the upper side of the auxiliary cylindrical reflector, the lower side of the auxiliary cylindrical reflector, the left side of the auxiliary cylindrical reflector and the right side of the auxiliary cylindrical reflector form a box-shaped cavity through the upper cover plate, the lower cover plate, the left baffle and the right baffle respectively, the horn conducting feed on the box-shaped cavity is hidden inside the box-shaped cavity and a waveguide port in the rear portion of the horn serves as a feed port. The box-shaped fan-beam antenna can provide fan beams with a wide pitch (azimuth) range and a narrow azimuth (pitch) range, and is simple in structural form, easy to process and manufacture and very suitable for being applied to millimeter-wave and over-submillimeter-wave frequency bands.